Device for delivering an implant through an annular defect in an intervertebral disc

ABSTRACT

The present invention relates generally to devices and methods for delivering medical devices, such as implants, to desired tissue sites, such as the intervertebral disc. In one aspect, an intervertebral disc repair and diagnostic device that is minimally invasive and that provides precise access to the desired site is provided. In some aspects, the device and method are adapted to deliver, position and expand implants that are initially oriented and compressed for minimally invasive, yet precise and effective implantation.

RELATED APPLICATIONS

[0001] This application is a continuation of co-pending U.S. applicationNo. ______, filed Jun. 21, 2004, and claims priority under 35 U.S.C.§119(e) to U.S. Provisional Appl. No. 60/480,276, filed Jun. 20, 2003,herein incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates generally to devices and methodsfor delivering implants to an intervertebral disc. Specifically, in someembodiments, apparatus and methods for delivering implants that areoriented and compressed for minimally invasive, yet precise andeffective implantation are provided.

[0004] 2. Description of the Related Art

[0005] Various implants, surgical meshes, patches, barriers, tissuescaffolds and the like may be used to treat intervertebral discs and areknown in the art. Surgical repair meshes are used throughout the body totreat and repair damaged tissue structures such as intralinguinalhernias, herniated discs and to close iatrogenic holes and incisions asmay occur elsewhere. Certain physiological environments presentchallenges to precise and minimally invasive delivery.

[0006] An intervertebral disc provides a dynamic environment thatproduces high loads and pressures. Typically, implants designed for thisenvironment, unless used for temporary purposes, must be capable ofenduring such conditions for long periods of time. Also, the difficultyand danger of the implantation procedure itself, due to the proximity ofthe spinal cord, limits the size and ease of placement of the implant.In light of the inherent limitations involved with delivery of medicaldevices to the disc environment, such devices should preferably bedelivered precisely with respect to the location of the defect.

SUMMARY OF THE INVENTION

[0007] In one embodiment of the present invention, devices and methodsfor delivering implants to an intervertebral disc are provided. In apreferred embodiment, delivery methods are designed to prevent or reduceexacerbation of the existing defect or iatrogenic hole. One of skill inthe art will understand that several embodiments of the invention can beused to deliver implants, or other medical devices, to sites in the bodyother than the intervertebral disc. For example, several embodiments ofthe invention can be used to deliver medical devices (such as implants)into the heart, bladder, liver, cranium, vertebrae, femur and otherbones

[0008] In one embodiment, a method of delivering and positioning amedical device (such as an implant) within an intervertebral disc isprovided. In one embodiment, the method comprises providing a cannula,an advancer, one or more expanders and an implant. The advancer is atleast partially coupled to, slideably engaged to, or housed within thecannula. The advancer is coupled to an implant, or is operable to becoupled to an implant. The implant is operable to exhibit a compressedprofile along one or more axes. The method further comprises compressingthe implant along a first axis, and inserting the cannula into ainterverterbral disc. The method further comprises positioning thecannula in the disc such that the implant is positioned beyond theinnermost surface of the anulus, rotating the cannula or advancer,retracting the cannula, thereby initially expanding the implant,advancing one or more expanders, thereby further expanding the implant,advancing the cannula, thereby substantially completely expanding theimplant, uncoupling the implant from the advancer, and removing thecannula and the advancer from the disc. In one embodiment, the cannulaor advancer is rotated clockwise or counterclockwise to enable theimplant to be rotate in a range from about 80 degrees to about 120degrees. Preferably the implant is rotated about 90 degrees. In otherembodiments, the above steps are performed using a medical device otherthan an implant. In some embodiments, the medical device (such as animplant) is delivered to a site other than the disc. These sitesinclude, but are not limited to, the heart, cranium or femur. In oneembodiment, one or more depth stops are coupled to the cannula,advancer, or delivered as a separate component. In one embodiment, whenthe cannula is inserted into the disc, the depth stop is placed at aposition adjacent an external surface of an intervertebral disc and theimplant is delivered relative to that position.

[0009] In one embodiment, the step of compressing the implant comprisesfolding the implant. In other embodiments, compressing the implantcomprises folding, deflating, compacting, compressing, closing orcondensing the implant, or a combination thereof.

[0010] In one embodiment, the step of expanding the implant comprisesunfolding the implant. In other embodiments, expanding the implantcomprises unfolding, inflating, enlarging, swelling, or opening theimplant, or a combination thereof.

[0011] In one embodiment, the implant is a barrier or patch. Implantssuitable for implantation according to one or more embodiments of theinvention include the implants described in U.S. Pat. Nos. 6,425,919,6,482,235, and 6,508,839, all herein incorporated by reference.

[0012] In a further embodiments, one or more implants are insertedthrough a defect or iatrogenic hole.

[0013] In one embodiment, a method of delivering a medical device (suchas an implant) within an intervertebral disc is provided. In oneembodiment, the method comprises providing an implant that is capable ofexhibiting a compressed profile along one or more axes, compressing theimplant along a first axis, inserting the implant within anintervertebral disc along a second axis and beyond the innermost lamellaof an anulus lamella, rotating the implant about an axis perpendicularto the second axis; and causing or allowing the implant to transformfrom a compressed profile to an expanded profile.

[0014] In another embodiment, a method of delivering a medical device(such as an implant) within an intervertebral disc comprises providing adelivery device having an elongate implant advancer carried within oralongside an elongate sleeve. In one embodiment, the advancer isreleaseably coupled to an implant, wherein the implant is compressedwithin the sleeve at a distal end of the sleeve. The method furthercomprises advancing the distal end of the sleeve with an intervertebraldisc along a first axis, rotating the advancer, releasing the implantfrom the sleeve thereby decompressing the implant, and releasing theimplant from the advancer.

[0015] In a further embodiment, a method of delivering a medical device(such as an implant) in an intervertebral disc wherein the disc has adefect or iatrogenic hole forming a void in the anulus of the disc isprovided. In one embodiment, the method comprises providing acompressible implant having a first and second axis, compressing animplant along a first axis, orienting the implant to such that the shortaxis of the compressed implant presents a profile the is smaller thanthe largest dimension of the void, inserting the implant beyond thedefect or iatrogenic hole, rotating the implant clockwise orcounterclockwise about ninety degrees, causing or allowing the implantto expand or unfold, and retracting at least a portion of the implantagainst an inner surface of the anulus.

[0016] In yet another embodiment, a method of delivering a medicaldevice (such as an implant) in an intervertebral disc along an innermostsurface of an anulus of the disc is provided. In one embodiment, themethod comprises inserting the implant through and beyond the innermostsurface of the anulus, retracting the implant toward the innermostsurface of the anulus, and deflecting at least a portion of the implantagainst the innermost surface of the anulus, thereby causing the implantto advance laterally along said surface.

[0017] In yet another embodiment, a method of delivering a medicaldevice (such as an implant) in an intervertebral disc along an innermostsurface of an anulus of the disc is provided. In one embodiment, themethod comprises inserting the implant within the disc and beyond theinnermost surface of the anulus, retracting the implant toward theinnermost surface of the anulus, and deflecting at least a portion ofthe implant against the innermost surface of the anulus, thereby causingthe implant to advance laterally along said surface. In one embodiment,the implant is expanded. In some embodiments, the method furthercomprises simultaneously retracting and deflecting the implant. In severembodiments, the method further comprises simultaneously retracting anddeflecting the implant in a synchronized manner. In a preferredembodiment, the method comprises rotating the implant.

[0018] In one embodiment of the invention, a device for delivering andpositioning an implant within an intervertebral disc is provided. In oneembodiment, the device comprises a cannula and an advancer. In oneembodiment, the cannula has a proximal end and a distal end, wherein thedistal end comprises one or more expanders operable to expand an implantpositioned beyond the innermost lamella of a disc anulus. In oneembodiment, the advancer has a proximal end and a distal end, whereinthe advancer is positioned at least partially within the cannula. Thedistal end of the advancer comprises a coupling mechanism, wherein thecoupling mechanism is coupled to the advancer and to the implant. Inanother embodiment, the expanders are not located on the cannula, butinstead coupled to the advancer. In one embodiment, the expanders arelocated on a separate instrument. In one embodiment, the devicecomprises one or more depth stops. The depth stop can be coupled to anyportion of the cannula or advancer, or can be independently delivered.In one embodiment, the depth stop is operable to limit and/or guidetravel within the intervertebral disc. In a further embodiment, thedepth stop is rotatably coupled to the cannula, thereby allowing it torotate while the depth of the cannula is maintained.

[0019] In one embodiment, the advancer is advanced through a sheath orother constraining means, and no cannula is used. In another embodiment,the advancer is coupled to a constraining means at its distal end thatis operable to constrain the implant until the implant reaches thedesired site (such as a site located beyond the innermost lamella of theanulus)

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIGS. 1A-1C show disc anatomy. FIGS. 1A and 1B show the generalanatomy of a functional spinal unit. FIG. 1A is a view of a transversesection of a functional spinal unit. FIG. 1B is a view of a sagittalsection. FIG. 1C shows the same functional spine unit with a defect inthe anulus, which may have been created iatrogenically, as in theperformance of an anulotomy, or may be naturally occurring.

[0021]FIGS. 2A-2D are front views of a delivery device and its elementsin accordance with an embodiment of the present invention.

[0022]FIGS. 3A-3E show embodiments of a delivery device. FIG. 3A is anisometric view of another delivery device in accordance with anembodiment of the present invention. FIG. 3B is an isometric view of theabove delivery device loaded with an implant folded in place at theslotted distal end of the cannula. FIG. 3C is an isometric view of theabove delivery device loaded with an implant in an unfoldedconfiguration. FIG. 3D is an isometric partial view of the distal end ofa delivery device loaded with a folded implant. FIG. 3E is across-sectional partial view of the distal end of an unloaded deliverydevice showing the implant coupling member.

[0023]FIGS. 4A-4B show aspects of the disc. FIG. 4A is a side view of afunctional spinal unit showing a defect in the posterior anulus of thedisc. FIG. 4B is a side view of a functional spinal unit showing adelivery device inserted within the disc.

[0024]FIGS. 5A-5G illustrate one method of delivering an implantaccording to one embodiment of the invention. FIG. 5A is an axial viewof the cross-section of an intervertebral disc with a delivery deviceinserted within the disc.

[0025]FIG. 6 is an axial view of the cross-section of an intervertebraldisc showing an implant situated along the posterior of the anulus andimplanted relative to a defect.

[0026]FIGS. 7A-7D show aspects of the implant. FIG. 7A shows an implantcompressible along two axes which can be used with various embodimentsof the invention. FIG. 7B is a top view (as it would be viewed along thesuperior-inferior axis of a vertebral in its implanted orientation) ofan implant and lateral extensions or stabilizers. FIG. 7C shows the sameimplant folded or compressed in an accordion like manner to facilitateloading into the cannula. FIG. 7D is an isometric view of anotherimplant suitable for use with some embodiments of the invention having aconcavity along its length and extensions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0027] Several embodiments of the invention will be discussed hereinthrough the demonstration of its use in the spine, with particularemphasis on intervertebral disc treatment. One of skill in the art willcertain understand that several embodiments of the invention can be usedto access or treat other sites in the body.

[0028]FIGS. 1A and 1B show the general anatomy of a functional spineunit. In this description and the following claims, the terms ‘anterior’and ‘posterior’, ‘superior’ and ‘inferior’ are defined by their standardusage in anatomy, e.g., anterior is a direction toward the front(ventral) side of the body or organ, posterior is a direction toward theback (dorsal) side of the body or organ; superior is upward (toward thehead) and inferior is lower (toward the feet).

[0029]FIG. 1A is an axial view along the transverse axis M of avertebral body with the intervertebral disc 315 superior to thevertebral body. Axis M shows the anterior (A) and posterior (P)orientation of the functional spine unit within the anatomy. Theintervertebral disc 315 contains the anulus fibrosus (AF) 310 whichsurrounds a central nucleus pulposus (NP) 320. Also shown in this figureare the left 370 and right 370′ transverse spinous processes and theposterior spinous process 380.

[0030]FIG. 1B is a sagittal section along sagittal axis N through themidline of two adjacent vertebral bodies 350 (superior) and 350′(inferior). Intervertebral disc space 355 is formed between the twovertebral bodies and contains intervertebral disc 315, which supportsand cushions the vertebral bodies and permits movement of the twovertebral bodies with respect to each other and other adjacentfunctional spine units.

[0031] Intervertebral disc 315 is comprised of the outer AF 310, whichnormally surrounds and constrains the NP 320 to be wholly within theborders of the intervertebral disc space. Axis M extends between theanterior (A) and posterior (P) of the functional spine unit. Thevertebrae also include facet joints 360 and the superior 390 andinferior 390′ pedicle that form the neural foramen 395. The facet jointsand intervertebral disc translate motion and transfer load between theadjacent vertebral bodies. This complex biomechanical arrangement allowsfor flexion, extension, lateral bending, compression, and can withstandintense axial loading and bending cycles of around a million per year.The disc height can vary from 50% to 200% of its resting value.

[0032]FIG. 1C shows the same functional spine unit with a defect in theanulus, which may have been created iatrogenically, as in theperformance of an anulotomy, or may be naturally occurring. Such adefect can be repaired, in one embodiment, using a surgical mesh ortherapeutic mesh, or the like. In one embodiment, the mesh can beimpregnated or coated with therapeutic agents or drugs to regrow orotherwise stimulate healing or growth or ingrowth as described herein.

[0033] In one embodiment of the invention, a method and device capableof delivering a therapeutic implant in a minimally invasive manner isprovided. In a preferred embodiment, delivery provides accurate andprecise placement of the implant, while still being minimally invasive.In one embodiment, the implant is placed along a tissue surface in anexpanded or manipulated configuration and orientation that differs fromthe insertion configuration and orientation.

[0034] In several embodiments, methods and apparatuses for deliveringsurgical meshes, barriers, patches, or the like, for treatment oraugmentation of tissues within pathologic spinal discs and otherstructures are provided. In one embodiment, a dynamic and synergisticdelivery method and device that allow for an integrated re-orientation,expansion and delivery of an implant in a confined and limitingenvironment is provided.

[0035] According to one embodiment, an instrument designed to assist inthe delivery and positioning of a implant within or adjacent to thevarious tissues generic to intervertebral disc, including the vertebralbodies and their endplates, the anulus fibrosis, the nucleus pulposus,and the surrounding ligaments, is provided.

[0036] One advantage of several embodiments of the invention areparticularly advantageous because, in some indications, a practitionerhas to deliver an implant or other medical device that has a complicatedconfiguration. For example, some implants have one or more dimensions intheir implanted or deployed state that make it difficult or impossibleto insert due, for example, to physiological size or geometricalconstraints. Such implants may have a second dimension which is alsolarger than the allowed dimensions available for insertion. For example,the height of the implant may be greater than the height of the openingor anulotomy or the height of the space between the adjacent endplatesat their. Further, the length of some implants may also be larger thanthe width anulotomy.

[0037] In one embodiment, an instrument and method that can effectivelydeliver medical devices to a desired site is provided. The method isparticularly advantageous for delivering medical devices havingchallenging configurations. In one embodiment, the method comprisesfirst inserting the implant rotated relative to the limiting dimensionto achieve a diminished or compatible profile and then rotating theimplant back to the desired orientation and expanded during finalpositioning. In a preferred embodiment, this method is accomplishedusing a single instrument. Other embodiments comprise using two or morecompatible instruments.

[0038] In one embodiment of the invention, a delivery device comprisinga cannula, a proximal end and a distal end is provided. In oneembodiment, the elongated, hollow cannula or sleeve has a proximal endfor handling by a physician and a distal end for inserting within apatient is provided. The distal end of the cannula can be dimensioned tofit within a small anulotomy as might be created by a surgeon or througha naturally occurring hole or lesion in the anulus.

[0039] In a further embodiment, an implant guide or advancer is carriedwithin the cannula or sleeve. In one embodiment, the guide or advanceris releaseably coupled to an implant that may be compressed within thecannula along one or more axes. In one embodiment, the guide or advanceris axially moveable within the cannula and can rotate depending on theimplant used or implantation site selected. The cannula functions as aguide for the axial reciprocal movement the advancer. As such, in oneembodiment, the cannula can, therefore, be provided in the form of anelongate tube having a central lumen for receiving advancertherethrough. Alternatively, the cannula can comprise a nontubularstructure or simply a sleeve or partial restraining member in anembodiment in which the advancer travels concentrically over oralongside it.

[0040] In one embodiment, a substantially rectangular implant isprovided. In several embodiments, the implant is a mesh comprised ofnitinol, steel, or polymer, or a combination thereof. In otherembodiment, the implant comprises a seeded or unseeded tissue scaffold,such as collagen or small intestine sub mucosa, and the like.

[0041] In one embodiment, the implant can be folded across its longaxis, connected to the advancer, and inserted within the sleeve at thedistal end of the delivery device. If the fold created along the shortaxis is larger that the sleeve diameter then one or more slots can beformed at the tip of the sleeve to accept the implant. Alternatively,the implant can be compressed along the second or short axis of theimplant so that both dimensions are held compressed within the sleeve.One of skill in the art will understand the implant, if needed, can becompressed along any axis in accordance with several embodiments of theinvention. Compressing the implant (or medical device), as used herein,shall be given its ordinary meaning and shall also include folding,deflating, compacting, compressing and condensing the implant or medicaldevice.

[0042] In one embodiment, in use, the distal end of the sleeve isinserted into the desired organ or tissue structure, such as anintervertebral disc. The implant is loaded into the sleeve such that thefold is at or near the distal end of the sleeve. Depending on the shapeof the insertion site (e.g., a rectangular anulotomy), and itsorientation (vertical or horizontal), the implant or advancer can berotated in order to pass through the aperture regardless of the desiredimplantation orientation. Accordingly, devices according to one or moreembodiments of the invention can cause the implant to rotate betweenaround 5 and 150 degrees and preferably between around 60 and 120degrees. In one embodiment, at least a portion of the delivery device isrotated clockwise or counterclockwise in the range of between about 2 to170 degrees, preferably between about 50 to 140 degrees, more preferablyabout 80 to 120 degrees, thereby enabling rotation of the implant. Inone embodiment, the device or the implant is rotated about 90 degrees.

[0043] In one embodiment, as the sleeve loaded with the compressedimplant is inserted medially into the disc, the surgeon may stopinserting when the edges of the folded-over implant pass beyond thecorresponding tissue surface against which implantation is desired. Inthis example, the surgeon would stop after passing the anulus or theouter and more narrow gap between the periphery of the adjacentvertebral endplates. Thereafter, the implant can be rotated about anaxis perpendicular to the insertion axis to correspond to the desiredinsertion orientation. Next, the sleeve is retracted relative to theadvancer to reveal the folded (and now unrestrained or activelycompressed) implant. Depending on the orientation of the implant withinthe sleeve (after the rotation step), the implant will expand inferiorlyand superiorly with respect to the endplates or laterally to the leftand right along the anulus. In one embodiment, as the implant unfoldsdue to its inherent resilience, or by a force imparted by the couplingmember or cannula, or by active manipulation by the physician, theadvancer is then retracted such that the folded part of the implant ispulled posteriorly in the direction of the posterior anulus and thesides or extensions of the implant advance laterally or travel along theanulus surface. When the action of the advancer causes the implant to befully retracted flat along the tissue surface or is otherwise in itsfully expanded position then the surgeon may detach the implant from theadvancer.

[0044] One of ordinary skill in the art will understand the kinematics,order, relative position, and orientation of the implant, sleeve, andadvancer can be reversed or altered to achieve similar or equivalentresults for a given implantation according to several embodiments to theinvention. For example, in one embodiment, the advancer can be used toextrude the implant out from the sleeve. In another embodiment, thesleeve can be retracted relative to the advancer. In a furtherembodiment, the advancer can be retracted to pull the implantposteriorly and along the posterior anulus or alternatively, the wholedevice (including the sleeve or cannula and advancer) can be pulledback. Both the advancer and the sleeve independently or the deviceitself can be used to rotate the implant. In one embodiment, at least apotion of the device remains stationary while one or more of itselements are manipulated. In another embodiment the delivery device issimplified with the use of a constraining member used in place of thesleeve to hold the implant in a compressed state at the distal end ofthe advancer. For example a suture, clamp, ring, band, pincher, or anadhesive could be used to constrain the implant and then the advancercould still server to advance the implant within the disc and rotate itinto position.

[0045] In several embodiments, parts of the device can serve differentpurposes during steps of the implantation. In one embodiment, the sleevecan constrain and then release the folded or compressed implant andlater, when the implant is released and in a slightly expanded state(larger that the profile of the cannula opening or tip), the cannula canbe advanced (or the advancer can be retracted) such that the cannula orsleeve tip contacts the inside surface of the folded sides of theimplant and forces them to open. Accordingly, in one embodiment, theretracting step involving posterior movement of the midsection of theimplant and lateral movement of the sides of the implant along theanulus surface caused by the opposing force of the anulus causinglateral deflection may be unnecessary since the opposing andsynchronized action and relative motion of the advancer and cannula tipeffectively act like a lever and fulcrum to open, expand or unfold theimplant. In one embodiment, the connector at the fold or hinge of theimplant acts like a fulcrum and the distal tips of the cannula act likelevers to push the fold flat and open the implant. This alternative orcomplimentary step or method of opening may be particularly useful inexpanding the implant proximal to a large defect of weakened portion ofthe anulus since such tissue might not offer a solid deflection surfacefor the opposing ends of the implant to advance along.

[0046]FIGS. 2A-2D show one embodiment of the invention. A deliverydevice 10 is shown having an elongate cannula having a proximal end 1and distal end 2. The cannula 15 has a distal end tip 20 or ends 20, 20′formed by a slot 21 cut into its distal end 2 for accepting andconstraining a compressed implant 100. Also shown are the cannula fingerhandles 5, 5′, advancer 30, advancer ring handle 25 at the proximal end1 and implant/advancer coupling member 35 at the distal end 2 of thedevice.

[0047] In one embodiment, a coupling member 35 is used. The couplingmember 35 is any device or mechanism that is capable of attaching orconnecting the implant in reversible manner. Coupling members include,but are not limited to, sutures, snaps, locks, lynch pins or the like,levers and slots, or any active or passive linking mechanism known inthe art that would permit a surgeon to disengage the implant at thedesired point of the procedure. In one embodiment, one or more couplingmembers are used. In one embodiment, two coupling members are used toconnect the implant.

[0048] In one embodiment, the device 10 is designed to be operated byone hand, e.g., utilizing the thumb, index, and ring fingers to positionthe device 10 and advance and retract the advancer 30. However, oneskilled in the art will understand that any of a variety of proximalhandpieces can alternatively be used, including, but not limited to,triggers, slider switches, rotatable knobs or other actuators to advanceand retract the advancer 30.

[0049] In one embodiment, the delivery device 10 can be manufactured inaccordance with any of a variety of techniques well known in the medicaldevice arts. In one embodiment, the cannula 10 comprises a metal tubesuch as stainless steel or other medical grade metal. Alternatively, thedevice 10 can comprise a polymeric extrusion, such as high densitypolyethylene, PTFE, PEEK, PEBAX, or others well known in the medicaldevice arts.

[0050] In a preferred embodiment, the axial length of the deliverydevice 10 is sufficient to reach the desired treatment site from apercutaneous or small incision access through the skin. In oneembodiment, the length of the delivery device 10 is within the range ofabout 10 centimeters to about 30 centimeters with a length from aproximal end to distal end within the range of about 10 to about 20centimeters contemplated for most posterior lateral access pathways. Thelength can be varied depending upon the intended access pathway andpatient size.

[0051] In one embodiment, the outside diameter of the delivery device10, and the distal end of the cannula 30, is no greater than necessaryto accomplish the intended functions disclosed herein. In oneembodiment, outside diameters of less than about one centimeter arepreferred. In preferred embodiments of the present invention, thecannula 30 has an outside diameter of no greater than approximately 5millimeters.

[0052] An exemplary embodiment having additional features is presentedin FIGS. 3A-3E. FIG. 3A is an isometric view of an implant deliverydevice 200 having a proximal end 1 for manipulating by a surgeon and adistal end for inserting with a patient. In one embodiment, an implantadvancer or guide 130 having a handle 125 located at the proximal end 1of the device 200 and an implant coupling member 135 extending to thedistal end 2 of the device 220 is provided. The advancer 130 isslideably housed within a cannula 115 which has a cannula handle 105 forpositioning and controlling the cannula.

[0053] The device, in one embodiment, also includes a distal depth stop150 feature that provides a limit and guide to the anterior/posteriorpositioning of the implant during implantation and in the finalpositioning of the implant. The depth stop 150 and 150′ is carried bythe cannula 115 and can be adjusted to rest along certain points of itslength by manipulating the depth stop adjustment member 155 and holdingthe depth stop handle 160. A calibrated measuring surface 156 can beetched onto to the cannula or attached separately to the cannula as asleeve to display depth correlations. Alternatively, non adjustabledepth stops in a variety of lengths can be included as a kit and theprecise depth stop for a given procedure can be selected preoperatively.In one embodiment, the depth stop 150 can be coupled to the cannula suchthat free rotation of the cannula 115 and advancer 130 are possiblewhile maintaining the desired depth of the distal tip of the device.

[0054] In a further embodiment, to assist opening or expanding theimplant, an implant expander 170 having a wedge surface(s) 175, 175′ atits distal end an expander handle 140 attached at its proximal end iscarried within the cannula 115 and over or along each side of theadvancer 130. One or more expanders can be coupled to the cannula or theadvancer. In one embodiment, a separate instrument comprising one ormore expanders at its distal end is passed through the cannula.

[0055] In FIG. 3B, a delivery device according to one embodiment of theinvention is shown loaded with a compressed implant 100 at the distalend 2 of the device 200. As shown, in one embodiment, the rectangularimplant 100 is folded over itself across its longs axis and fittedwithin a slot of the cannula formed by the slotted ends of the cannula120 and 120′. In an alternative embodiment, the cannula could bestraight (e.g., no slot formation) and the implant could also becompressed along its second or short axis. FIG. 3C shows the devicecoupled to an expanded or unfolded implant 100.

[0056]FIG. 3D shows an enlarged isometric view of the distal end of thedevice 200 loaded with an implant 100 between slotted end tips or tongs120, 120′ of the cannula 115. The opposing distal ends of the depth stop150, 150′ are shown as forked protrusions adjacent the cannula 115. Inone embodiment, two depth stops are provided. In another embodiment, oneor more depth stops are provided. In an alternative embodiment, anentire circumferential stop surface can be used.

[0057]FIG. 3E shows the cross-section of the distal end of the device200 including the expanders 175, 175′ and implant/advancer couplingmember 135. In one embodiment, the coupling member is a flexible “T-bar”attached lengthwise to the advancer 130 and fits into slots in theimplant surface (not shown). Alternatively, active and passive couplingmeans described above can also be used. In one embodiment, when theexpanded implant is retracted against the tip of the cannula 120 and/orthe anulus surface (which is shown oversized in comparison to the mouthof the cannula or insertion site), further retraction of the advancer orthe device its causes the coupling member to slip out of the slots (notshown) in the implant. Also shown are radio opaque indicators 150, 150′coupled to the depth stop 150, 150′ which can be used in determiningdevice placement during radiographic imaging. For example, portions ofthe device can be aligned with anatomical structures or the handles orother projections of the device can be oriented to correspond to theimplants orientation. One or more radio opaque markers can be used inone embodiment of the invention. One of skill in the art will understandthat other indicators or markers can also be used. Turning to FIGS. 4Aand 4B, a side view of a functional spinal unit is shown with a defect300 in the anulus 310 (see e.g., FIGS. 1A-1C for vertebral anatomy) andthe device 200 inserted in the defect. In one embodiment, a posteriorlateral approach that can involve a laminotomy or modification of theposterior elements of the adjacent vertebral bodies is used. In afurther embodiment, other approaches can be used, including, but notlimited to, anterior (e.g., through the abdomen or neck), lateral (e.g.,transpsoas), or inferior (e.g., trans-sacral) approaches.

[0058] The series presented in FIGS. 5A through 5G depict a sequence fordelivering a generally elongate rectangular mesh implant according to anembodiment of the method. The defect 300 or box or slit anulotomy isrectangular in shape having a lateral (or width) dimension greater thanits vertical dimension. Moreover, the vertical dimension may also belimited by the relative location of the endplates at the time ofprocedure limiting the height of a deliverable implant. In oneembodiment, the implant 200 is oversized to cover the defect 300 and tofunction as a barrier situated against the anulus 310 along itsinnermost lamella.

[0059]FIG. 5A is an axial view of a cross-section of the disc showingthe implant 100 folded along its long axis and connected to the advancer130 (not shown) and inserted within the distal end tips or tongs 120 ofthe cannula 115. Here, the fold created along the short axis is largerthat the cannula 115 diameter so a slot is formed at the tip of thecannula 115 formed by opposing tips 120, (120′ not shown). Thisarrangement permits the distal end of the device 2 loaded with theimplant to be advanced within and then beyond the defect 300 and theanulus 310 as shown in FIG. 5B. Here the depth stop 150, 150′, 150″ isshown as three protrusions though more or less can be used. In thisdelivery application, portions of the depth stop 150 can be placedagainst the anulus or one or both of the adjacent vertebral bodies. Inother embodiments, the depth stop 150 can be placed on, abut or engagethe exterior of an organ, such as the heart, a bone such as cranium,femur, or vertebral body. In one embodiment, the implant is designed tohave a preferred region of final placement in terms of its positioningtoward the anterior or posterior of the disc (anterior being defined asthe direction toward the front of the patient and posterior beingdefined as the direction toward the back of the patient) in front of thedefect. The surgeon may also want to place the implant and have thedelivery device provide a limit or guide to the distance toward theanterior of the disc in order to prevent damage to the anterior anulusor damage to anatomy anterior of the disc such as the aorta. Similarly,the surgeon may want to place the implant in a position that is not toofar posterior within the disc to prevent damage to the posterior anulusor anatomy posterior to the disc such as the spinal cord and its duramater or the posterior longitudinal ligament.

[0060]FIG. 5C shows the next step in the aforementioned method whereinthe cannula 115 is rotated 90 degrees (after clearing the anulus). FIG.5D shows the implant already unfolding or otherwise changing itstransverse profile. In one embodiment, as shown, the gap between theopposing ends of the implant 100 is increasing as is the angle of thefold created at the implant/advancer coupling member 135. As discussedearlier this initial unfolding can be the product of a variety offactors including the inherent resiliency of the implant 100 or thecoupling member 135.

[0061]FIG. 5E shows the advancement of wedge-tipped expanders 175 whichcan aid or replace the initial unfolding step described above. Theexpanders 175, in one embodiment, are wedge-tipped. In otherembodiments, the expanders can be shaped in any form that permitsufficient contact with the implant to lever it open or otherwisereconfigure it, including but not limited to flat or rounded shapes.Additionally, other embodiments may include expanders comprisingballoons, springs, elastic members, or mechanical linkages adapted toexpand or reconfigure the implant

[0062]FIG. 5F shows the advancement of the cannula tip 120, 120′ toassist the expanders in opening the implant 100. In one embodiment,advancer 130, expander 175, and implant 100 can be retracted against thedistal end of cannula 120 and implant 100. Force between cannula tip 120and implant 100 acts to expand implant 100 while minimizing forcesbetween implant 100 and the anular wall. This retraction of implant 100,advancer 130, and expander 175 can be done at a different rates orsnychronized or to different extents relative to the retraction ofcannula 120 to generate this force and/or open implant 100 to a greateror lesser extent during retraction of implant 100. In one embodiment,this opening step is particularly advantageous in instances where thetissue surface upon which the implant is to be positioned in weakenedand would otherwise provide a poor deflection surface or if the defectis large such as would allow the implant to be pulled back through thedefect instead.

[0063]FIG. 5G show the final steps of delivery, in one embodiment,wherein the implant 100 is pulled towards the posterior of the anulus310 as the ends of the implant 100 are deflected and advanced laterallyalong its inner surface. This posterior travel can be caused when theadvancer 130, cannula 120, and expander 175 are retracted in unison. Atthis point the coupling member 135 is disengaged from the implant 100and the device is removed from the patient. Note that, in one embodimentthat substantially throughout the procedure the depth stop 150 maintainsrelative position so that the surgeon is certain of the placement of thedevice along the anulus surface. The retraction of the various elementsof the system can be coordinated relative to depth stop 150 to minimizeforces on surrounding tissues or optimize expansion or position ofimplant 100 relative to defect 300. FIG. 6 shows a fully implanteddevice 100 (this implant being sized to cover the entire posterioranulus) and the blocked-off defect 300.

[0064] In several embodiments, relatively simple rectangular meshes orpatches are provided for implantation. In other embodiments, morecomplex devices can be used, including, but not limited to stents,grafts, arterial septal defect closure devices and the like. FIG. 7Ashows an elongated implant 200 with two vertical extensions 202, 204that can be oriented, folded, and expanded according to the teachings ofvarious embodiments of the invention. FIG. 7B shows an implant withlateral extensions 204, 204′ as might be used to cover the posterior andlateral walls of an anulus. FIG. 7C shows the implant 200 exhibitingmultiple folds along its long axis to compress its delivery profile.Finally, FIG. 7D presents a concave elongate member that has lateralextensions 204, 204′ and midline lateral extensions 206, 206′. Thisdesign also permits folding and compression along one or more axes andcan be delivered according to the teachings herein.

[0065] As part of an implantation procedure according to one embodimentof the invention, active and passive systems can be incorporated intothe delivery devices or the implants to aid the in preparation of thedelivery site or in manipulating the implant. For instance, in oneembodiment, a gas, liquid and/or solid component can be added to theimplant during positioning or after positioning to further reshape theimplant or adjust its size. In some embodiments, the implant comprisesone or more pharmaceutical agents. The pharmaceutical agent canfacilitate pain reduction or inhibition of scarring, and can includegenetically active growth or healing factors. In a further embodiment,lubrication is provided to reduce friction as the implant exits thedelivery device. One or more pharmaceutical agents can also be providedby or through the cannula or advancer. In yet another embodiment,materials that aid in the visualization of the implant are provided,including, but not limited to, material for radio opaque locationthrough a radiograph. Visual markers can be located on the implantand/or the delivery device.

[0066] In one embodiment, the implant can be anchored to adjacent ornearby tissue and an anchoring mechanism, such as a stapler, can beincorporated into the delivery device. In another embodiment, amechanism for activating an anchoring mechanism can be contained withinthe implant itself. Heat, energy delivery from the electromagneticspectrum, or the removal of heat (chilling or freezing) can be employedbefore, after or during the implant deployment to aid in positioning,function of the implant, or related disc or spine treatments such as thevaporization of unwanted tissue, the deadening of pain receptors, andthe removal of bone or scar tissue. In one embodiment, means foradjusting the temperature of surrounding tissue is coupled to orintegral with the delivery device. In another embodiment, means foradjusting temperature is an instrument that is separate from thedelivery device.

[0067] In some embodiments, a delivery device comprises one or moreaxially extending lumens, for placing the proximal end of the device influid communication with the distal end, for any of a variety ofpurposes. For example, one or more lumens can extend through theadvancer 130. Alternatively or in addition, the outside diameter theadvancer can be dimensioned smaller than the inside diameter of thedelivery cannula 115 to create an annular space as is well understood inthe catheter arts. A first lumen can be utilized for introduction ofradiopaque dye to facilitate visualization of the progress of theimplant 100 and or distal end 2 of the device 200 during the procedure.The first lumen or second lumen can be utilized to introduce any of avariety of media. In one embodiment, one or more lumens are used todeliver saline solution. In another embodiment, one or more lumens areused to deliver pharmaceutical agents, including but not limited to,anti-inflammatory agents, steroids, growth factors (such as TNf-αantagonists), antibiotics, vasodilators, vasoconstrictors, andfunctional proteins and enzymes (such as chymopapain). In oneembodiment, one or more lumens is used to aspirate material, such asbiological fluids or nucleus pulposus. In another embodiment, one ormore lumens is used to introduce nucleus augmentation material, or otherbiological or biocompatible material, before, during or at the end ofthe procedure. In several embodiments, one or more lumens are used todeliver fluid, or other material, to a site to aid in heating or coolingthe site tissue.

[0068] While this invention has been particularly shown and describedwith references to preferred embodiments thereof, it will be understoodby those skilled in the art that various changes in form and details maybe made therein without departing from the scope of the inventionencompassed by the appended claims. In addition, one of skill in the artwill understand that the steps recited in some embodiments need not beperformed sequentially or in the order disclosed.

What is claimed is:
 1. A device for delivering and positioning animplant within an intervertebral disc comprising: a cannula having aproximal end and a distal end, wherein said distal end comprises one ormore expanders operable to expand an implant positioned beyond theinnermost lamella of a disc anulus; and an advancer having a proximalend and a distal end, wherein said advancer is positioned at leastpartially within the cannula; wherein the distal end of said advancercomprises a coupling mechanism, wherein at least a portion of saidcoupling mechanism is coupled to the advancer and wherein at least aportion said coupling mechanism is coupled to the implant.
 2. The deviceof claim 1, further comprising a depth stop for limiting or guiding thetravel within the intervertebral disc.
 3. The device of claim 1, whereinthe depth stop is rotatably coupled to the cannula thereby allowing itto rotate while the depth of the cannula is maintained.
 4. The device ofclaim 1, wherein the implant is a barrier or patch.
 5. The device ofclaim 1, wherein the implant is initially provided in a foldedconfiguration.
 6. The device of claim 1, wherein said one or moreexpanders are operable to unfold the implant.